Giant electromagnetic pulses (EMP) generated during the interaction of high-power lasers with solid targets can seriously degrade electrical measurements and equipment. EMP emission is caused by the acceleration of hot electrons inside the target, which produce radiation across a wide band from DC to terahertz frequencies. Improved understanding and control of EMP is vital as we enter a new era of high repetition rate, high intensity lasers (e.g. the Extreme Light Infrastructure). We present recent data from the VULCAN laser facility that demonstrates how EMP can be readily and effectively reduced. Characterization of the EMP was achieved using B-dot and D-dot probes that took measurements for a range of different target and laser parameters. We demonstrate that target stalk geometry, material composition, geodesic path length and foil surface area can all play a significant role in the reduction of EMP. A combination of electromagnetic wave and 3D particle-in-cell simulations is used to inform our conclusions about the effects of stalk geometry on EMP, providing an opportunity for comparison with existing charge separation models.

Recent results in the development of diode-driven high energy, high repetition rate, picosecond lasers, including the demonstration of a cryogenic Yb:YAG active mirror amplifier that produces 1.5 J pulses at 500 Hz repetition rate (0.75 kW average power) are reviewed. These pulses are compressed resulting in the generation of ${\sim}5~\text{ps}$ duration, 1 J pulses with 0.5 kW average power. A full characterization of this high power cryogenic amplifier, including at-wavelength interferometry of the active region under ${>}1~\text{kW}$ average power pump conditions, is presented. An initial demonstration of operation at 1 kW average power (1 J, 1 kHz) is reported.